1. Field of the Invention
The present invention relates to a vein authentication device and a vein authentication method.
2. Description of the Related Art
Biometric identity verification is a very important technology to protect rights in a future network society. Particularly in business transactions on the Internet in which another person can pose as a person in question and steal money, content, and privileges over the network, biometric identity verification has gained attention as a technology to protect such fields that are difficult to resolve by encryption alone. However, it is difficult for fingerprints and irises to resolve an issue of forgery. In this respect, a personal authentication technology using a pattern of vein in an area that is difficult to image easily from outside is expected as a next-generation biometric identity verification due to high-level determination precision and difficulty of forgery and impersonation.
Such a biometric identity verification technology includes, for example, a fingerprint authentication technology and a vein authentication technology. The fingerprint authentication technology has issues of presence of about 4% of users who are disabled to register their fingerprints and resistance to attacks using residual fingerprints for posing, but has an advantage that sensors can be miniaturized because images can easily be synthesized even by a scan type system using line sensors or area sensors. On the other hand, the vein authentication technology expected as a next-generation authentication technology having less such issues uses larger sensors and thus, it is difficult to mount the technology in mobile devices. Particularly in an imaging system in which transmission images of vein are used, planar structuring of a device is difficult due to strict limitations on the position of a light source.
Thus, in order to realize miniaturization of a device using vein authentication technology, Japanese Patent Application Laid-Open No. 2006-288872 uses a method by which the scan speed of a finger is detected from a picked-up image to reconfigure a picked-up finger vein image using a graded index lens array.